Other tips and advice
Bias (or diagonal) tyres
The carcass of a bias tyre is made from ply cords in layers arranged at an angle. The layers are placed so that the cords create a criss-cross pattern. The whole structure is uniform throughout; the crown and sidewalls of the tyre have similar mechanical properties.
With a radial construction, the ply cords radiate out from the centre of the tyre. In addition, the crown is made from layers that form a belt. As a result, the crown and sidewalls have their own particular characteristics.
Two kinds of tyres for specialised performance
Due to their soft sidewalls, the crowns of radial tyres stick to the road on contact. Their imprint, shorter but wider than that of a bias tyre, provides added grip when leaning in heavily on corners. The pressure of the air in contact with the tyre surface is distributed more effectively with radial tyres, which results in more even tread wear over time.
Radial tyres also provide greater comfort at higher speeds, once again as a result of their soft sidewalls, which absorb the impact of imperfections on the road surface. On the other hand, bias tyres are able to carry a greater weight because their sidewalls are more rigid. At high speeds, bias tyres can become so deformed that their performance is affected. Ultimately, bias tyres are suitable for vehicles travelling at moderate speeds, with small to medium-sized engines and flexible chassis. They are also suited to heavy motorcycles or those that are heavily loaded. Radial tyres are needed for more powerful vehicles with very rigid chassis and for more sporty purposes. They allow you to reach ZR speed ratings, above 240 km/h.